AMATRON ETL Listed 16" T9 24W LED Circline Bulb LED Circular Tube 5000K Daylight Frosted Lens with Non-Dimmable External Power Driver to Replace 16 inch 40W Fluorescent Circline - Led Household Light
4 Easy Ways to Change a Circular Fluorescent Light Bulb - wikiHow
913818-3 GE Lighting 22 Watts Circular Fluorescent Lamp, T9, 4-Pin (G10q), 1100 Lumens, 4100K Bulb Color Temp. | Imperial Supplies
22 Watt Fluorescent T9 Circline 8 In. Light Bulb with 4 Pin (G10Q) Base, 6500K - FC8T9/
Feit Electric 22-Watt 8 in. T9 G10q Linear Circline Fluorescent Tube Light Bulb, Warm White 3000K (12-pack) FC8T9/WW/12 - The Home Depot
Project 'Green' House #1: LED replacement lighting for circular fluorescent tubes // DavidJB.com // Python, Technology, Web, Linux, and more, by David Beitey